Cranial neural crest cells migrate in a highly specific manner and differentiate into many craniofacial structures. Neural crest cells in culture differentiate into two of their normal derivatives, neurons and melanocytes. As an approach toward understanding normal and abnormal neural crest development, we are (a) characterizing the factors which induce their differentiation, (b) examining chemotactic responses which may direct their migration, and (c) studying their interactions with extracellular matrix molecules.